JPS6067251A - Negative-pressure type booster - Google Patents

Abstract

PURPOSE:To permit certain seal for through holes by installing a plurality of locking hooks and a flange for preventing slip-off onto a seal installation cylinder for the installation of an expandable boot and locking the opened edge of each through hole of a booster piston and a diaphragm between the locking hooks and the flange for preventing slip-off. CONSTITUTION:A seal installation cylinder 83 is inserted into the through holes 79 and 81 which are formed onto a booster piston 5 and a piston diaphragm 6 respectively and into which a tie rod is inserted. A plurality of locking hooks 84 and a flange 86 for preventing the slip-off are formed onto the seal installation cylinder 83. The opened edges of the both through holes 79 and 81 are locked between the locking hook 84 and the flange 86 for preventing the slip-off, by turning the installation cylinder 83 after positioning the locking hook 84 at the cut part 80 of the through hole 79 and inserting the seal installation cylinder 83 into the through holes 79 and 81, and therefore these through holes 79 and 81 are certainly sealed. An expandable boot 94 is installed between the seal installation cylinder 83 and the annular groove of a tie rod.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a negative pressure booster used, for example, in operating a brake mask cylinder of a vehicle.

Conventionally, this type of device always communicates with a negative pressure source by a pair of front and rear bowl-shaped bodies, a booster shell inner metal, a booster piston that can freely reciprocate back and forth, and a piston diaphragm attached to the rear surface of the booster piston. It is divided into a first working chamber at the front and a second working chamber at the rear which is alternately controlled to communicate with the first working chamber or the atmosphere via a control valve, and includes a full histone diaphragm between both arm-shaped bodies and a booster piston. It is known that the double-speed hole is sealed by connecting multiple tie rods that completely pass through the double-speed hole formed in the.

When the arm-like bodies are connected multiple times by tie rods as described above, the stiffener shell can be molded from a lightweight material such as thin steel plate or synthetic resin to reduce the weight of the device due to the reinforcing action of the tie rods. I can do it.

In this case, if you do not seal both speed holes securely, air will leak from those holes and the booster piston will operate incorrectly. This will cause a hindrance to the assembly efficiency of power equipment.

In view of the above, it is an object of the present invention to provide a booster device that can easily and reliably seal both feed holes, and in which a plurality of notches are provided on the edges of the booster holes. By inserting and rotating a seal mounting cylinder, which has a plurality of locking claws corresponding to the notches and a retaining flange that faces each locking claw on the outer circumferential surface thereof, and rotating it, each of the locking claws The feature is that both the edges of the feed hole are clamped between the flange and the retaining flange, and a sealing means is provided between the seal mounting tube and the tie rond.

An embodiment in which the present invention is applied to a brake master cylinder will be described below with reference to the drawings.

In FIG. 1, booster shell 1 of negative pressure booster S
are a pair of front and rear bowl-shaped bodies IF, IR, 1, and a rear bowl-shaped body I made of lightweight thin-walled steel plate or synthetic resin.
A plurality of claw pieces 2 protruding from the opening of R at equal intervals on the circumference are engaged with a plurality of notches 3 formed at equal intervals on the circumference at the opening of the front bowl-shaped body 1F. The arms IF and IR are positioned relative to each other, and the front and rear opposing walls of the arms IF and IR are connected via a pair of tie rods 4. The connection structure between the booster shell 1 and the tie rod 4 will be described in 1 below. Ru.

The interior of the booster shell 1 includes a booster piston 5 housed therein so as to be able to reciprocate back and forth, a piston diaphragm 6 attached to the rear surface 5b of the booster piston 5, a first working chamber A at the front, and a rear part. It is divided into the second trial room B and the second trial room B.

The first working chamber A is always in communication with the intake manifold (not shown) of the internal combustion engine, which is a negative pressure source, through the entire negative pressure introduction pipe 7,
The second working chamber B is connected to the control valve 8 [via the first working chamber A], which will be described later.
Alternatively, the air inlet 11 opened in the end wall 10 of the rear extension tube 9 of the booster shell 1 is alternately connected and controlled.

The booster piston 5 is always urged in the backward direction, that is, toward the second working chamber B side, by the return spring 12 in which the first working chamber AVc is compressed, and its backward limit is reached by a protrusion 13 formed protrudingly on the back surface of the piston diaphragm 3. is regulated by contacting the inner surface of the rear wall of the booster shell 1.

The booster piston 5 is provided with a valve cylinder 14 that protrudes rearward from its center, and the valve cylinder 14 is slidably supported by a flat bearing 15 provided on the extension cylinder 9, and its rear end is connected to the atmosphere introduced into the cylinder 9. It is opened toward the mouth 11.

The control valve 8 is configured in the valve cylinder 14 as follows.

That is, an annular first valve seat 1ti is provided on the front inner wall of the valve cylinder 14.

is formed, and a valve piston 18 connected to the input rod 17 and forming the front end thereof is slidably connected to the front part of the valve cylinder 14.
An annular second valve seat 162 surrounded by the first valve seat 16□ is formed at the rear end of the valve piston 18.

On the inner wall of the valve cylinder 14, there is a cylindrical valve body 19 with both ends open.
The base end portion 20 of the valve body 1 is clamped via a valve body holding cylinder 21 that is fitted into the valve cylinder 1I. The valve body 19 is made of an elastic material such as rubber, and a thin diaphragm 22 extends radially inward from its base end 20, and a thick valve portion 23 is connected to the inner peripheral end of the valve body 19. The valve portion 23 is provided with the first and second valve seats 16□, 16. to face. Therefore, valve part 2
3 can move forward and backward 9 by deforming the diaphragm 22, and can also come into contact with the front end surface of the valve body holding cylinder 21.

An annular reinforcing plate 24 is embedded in the valve portion 23, and a valve spring 25 is connected to urge the valve portion 23 toward the valve seats 1&+ and 162.

The outer part of the first valve seat 16□ is connected to the first working chamber A through a pair of through holes 26 of the booster piston 5, and to the first and second
The middle part of the valve seat 161.16□ is connected to the second working chamber B through another pair of through holes 27, and the inner part of the second valve seat 162 is connected to the atmosphere inlet 11 through the inside of the valve body 19. Constant communication.

The booster piston 5 is provided with a large-diameter cylinder hole 28 that opens at the center of its front surface, and a lJX-diameter cylinder hole 29 that opens at the inner end surface of the cylinder hole 28. An elastic piston 3o made of rubber or the like and an output piston 31 with the same diameter as the heel are slid together, and a reaction piston 32 with a smaller diameter than the elastic piston 3o is slid into the small diameter cylinder hole 29. . Further, a small shaft 33 protruding from the front end face of the valve piston 18 enters the small diameter cylinder hole 29, so that the reaction piston 3
It faces the rear end surface of 2. An output rod 34 is protruded from the front surface of the output piston 31, and the output rod 34 is disposed within the first working chamber A.

The input rod 17I'i and the return spring 37 are always pushed in the backward direction, and the retraction limit is reached when the movable stopper plate 35 screwed onto the input rod 17 hits the inside of the end wall 10 of the rear extension tube 9. Contact with them is strictly regulated.

When the movable stopper plate 35 is rotated, the screwing position between the movable stopper plate 35 and the input rod 17 changes, so that the input rod 17 can be adjusted to the full retraction limit. After the adjustment, the movable stopper plate 35 is fixed by tightening a lock nut 36 which is also screwed onto the input rod 17. Movable horn and board 35
A vent hole 38 is formed in the vent hole 38 so that the air inlet port 11 is not blocked by the vent hole 38 .

At the outer end opening of the valve cylinder 14, filters 39 and 40 are installed which completely purify the air introduced from the atmospheric air inlet 11 and which can be deformed so as not to interfere with the operation of the input rod 17.

Next, the assembly structure of the valve cylinder 14 to the booster piston 5 will be explained. As shown in Figs. A valve cylinder fitting hole 41 is formed. The booster piston 5 has a pair of arc-shaped reinforcing ribs 42 that are arranged so as to surround the insertion hole 41 and protrude from the front surface 5a, and a front surface with tips facing each other on the outside of both reinforcing ribs 42. A pair of locking claws 4 cut out toward the 5a side
3 are provided. Both image retaining claws 43 are biased to one side of both reinforcing lips 42 and are arranged point-symmetrically with respect to the center of the insertion hole 41.

The valve cylinder 14 is molded from thermosetting synthetic resin such as phenol resin, and has a cylindrical main body 44 and a retaining flange 45 protruding from the outer peripheral surface of one end of the main body 44, The outer circumferential surface of the connecting portion of the main body 44 with the locking flange 45 is formed into a teno plane 46 with the flanges 5 side being the larger diameter side. The retaining flank 45 has the large-diameter cylinder hole 28 on its end face, and has a truncated conical short cylindrical portion 47 concentric with the main body 44, and a flat top surface 48 disposed to sandwich the short cylindrical portion 47. The first through hole 26 has a pair of protrusions 49 having a top surface 48 thereof.

Further, the other through hole 27 is opened on the small diameter side of the tapered surface 46.

The locking plate 50 includes a flat plate part 52 having a truncated conical cap part 51 into which the short cylindrical part 47 can be fitted loosely, and the flat plate part 5.
A pair of leg portions 35 are bent diagonally in a direction opposite to the protruding direction of the cap portion 51 at both ends of the leg portions 530, and a pair of locking portions 54 extend further outward from both ends of the leg portions 530. Become. The connecting portion between the flat plate portion 52 and the leg portion 53 is formed in an arc shape along the outer periphery of the retaining flange 45, and the connecting portion between the leg portion 53 and the locking portion 54 is formed in an arc shape along the outer periphery of the reinforcing rib 42. Each is formed.

Reinforcing edges 55 are formed by bending on both side edges of the locking plate 50 except for one end portion of the leg stopper 54 which is symmetrical with respect to the center of the cap portion 51 .

A through hole 56 having a smaller diameter than the output piston 31 and a larger diameter than the output rod 34 is formed in the top wall of the cap portion 51, and communicates with the through hole 26 on the base end side of the cap portion 51 of the flat plate portion 52. A pair of communication holes 57 are formed.

When assembling the valve cylinder 14 to the booster piston 5, the main body 44'f of the valve cylinder 14, the insertion hole 4 of the booster piston 5,
1 from the front surface 5a side, the retaining flange 45 is positioned inside the leg reinforcement 242, and the booster piston 5 is overlapped with the booster piston 5. Then, as shown in FIG. 4, the cap part 51 of the locking plate 50 is loosely fitted into the short cylindrical part 47, and the connecting part between the flat plate part 52 and the 14 part 53 is completely pulled out at a position where it is removed from the locking claw 43. At the outer peripheral edge of the stop flange 45, there are also a leg portion 53 and a locking portion 54.
The connecting portions are all aligned with the outer peripheral edges of the reinforcing ribs 42, respectively,
From this state, the locking plate 50 purple, its legs 53 and locking portions 54
When the connecting portion is brought into contact with the reinforcing rib 42 and is fully guided and rotated in the direction of arrow a in FIG. Climb onto the top surface 48 of 49, and attach the locking plate 50 and booster bis! - The valve cylinder 14 is assembled to the booster piston 5 with the stopper flanges 45 being clamped between the valve cylinders 75 and 75. In this case, the reinforcing edge 55 located at one end of the locking portion 5o collides with the edge of the locking pawl 43, and the rotation angle of the locking plate 5o is regulated.
The communication hole 57 of the locking plate 50 and the through hole 26 match. Further, the movable end of the return spring 12 engages with the cap portion 51 of the locking plate 5o, and the locking plate 50 is prevented from rotating by the elastic force of the return spring. The output rod 34 is connected to the cap portion 510 through hole 5
However, since the diameter of the through hole 56 is smaller than that of the output piston 31, the top wall 51a of the cap portion around the through hole 56 faces the opening of the cylinder hole 28 and faces the output piston 31. It functions as a stopper piece to
This prevents problems such as the output piston 31 and the output rod 34 falling from the valve cylinder 14 when the booster piston 5 is assembled.

1st. As shown in FIG. 3, the piston diaphragm 6 is formed with annular inner and outer peripheral beads 58 and 59, and the outer peripheral bead 59 has a positioning protrusion 6o protruding from its end surface in a rear bowl shape. It is fitted into each positioning hole 61 formed on the outer periphery of the body 1R and sandwiched between the arm-like bodies IF and IR.

The inner peripheral bead 58 is fitted into the edge of the insertion hole 410 of the booster piston 5, but in a free state, the inner peripheral bead 58 has a front surface 5a of the booster piston 5 as shown by the chain line in FIG.
A series of bulges 58a that protrude inward from the sides and the insertion hole 41
is formed. When the valve cylinder 14 is clamped between the retaining flange 45 and the booster piston 5 as described above, the bulging portion 58a is formed into a hole into which the retaining flange 45 is inserted as shown by the arrow -b. 41, and in the direction of the center line of valve cylinder 14.
The tapered surfaces 46 of the fitting holes 41 are strongly pressed radially outward as shown by arrow C and compressed into the annular recess 62 around the fitting holes 41, thereby ensuring a secure connection between the valve cylinder 14 and the booster piston 5. will be sealed.

The pressure receiving portion 63 of the piston diaphragm 6 is in close contact with the rear surface of the booster piston 5, and projects toward the first working chamber A between the outer circumferential surface of the booster piston 5 and the inner circumferential surface of the front bowl-shaped body 1F. It is bent into a U-shape, and the shift of this U-shaped bent portion allows the sive-staviston 5 to move forward and backward.

As shown in FIGS. 1 and 5, an opening 64 is formed in the portion of the booster piston 5 where the locking claw 43 is cut and raised, and the booster piston 5 and the piston diaphragm 6 are connected through the entire opening 64. Since the M1 working chamber AK is in communication with the M1 working chamber AK, no air pocket is generated between the two 5 and 6. Further, the portion of the piston diaphragm 6 facing the opening 64 is formed into a thick wall portion 65, whereby the atmosphere is introduced into the second working chamber B and the atmospheric pressure in the second working chamber B is increased to the first working chamber B. Even if the height of the working chamber A becomes higher than that of the working chamber A, the thick portion 65 will not bulge into the opening 64, and therefore the piston diaphragm 6 will not bulge out into the opening 64.
Damage caused by the opening 64 can be prevented.

Next, the connection structure between the tie rod 4 and the booster shell 1 will be explained.

As shown in FIG. 1, the tie rod 4 has a mounting bolt 66 that penetrates the front wall of the booster shell 1 and projects forward.
are integrally formed, and a spring receiving plate 67 that abuts the inner surface of the front wall of the booster shell 1 is fixed. Then, the mounting bolt 6'6 is passed through the mounting flange 68 of the brake master cylinder M stacked on the front surface of the booster shell 1, and the nut 69 is screwed onto the tip of the bolt 6'6 and tightened. The front wall of the shell 1 and the enclosure of the mounting flange 68 are connected together. At this time, an annular seal member 71 that seals the tie rod through hole in the front wall of the booster shell 1 is fitted into an annular groove 7o formed on the front surface of the spring receiving plate 67 so as to surround the bolt 66. The spring receiving plate 67 supports the fixed end of the return spring 12, and allows the elastic force of the return spring 12 to be borne by the tie rod 4, thereby removing the load on the booster shell 1.

Further, the tie rod 4 is integrally formed with a take bolt 72 that penetrates the rear wall of the booster shell 1 and projects rearward thereof, and a stepped flange 73 that abuts the inner surface of the rear wall of the booster shell 1. The stepped flange 73 is fitted into a support tube 74 that is welded and fixed to the inner surface of the rear wall of the booster shell 1, and its retaining monkey 75 is locked to the support tube 74, so that the tie rod 4 and the rear wall of the booster shell 1 are connected. connected together. At that time, the annular groove 7 between the small diameter part of the stepped flange 73 and the support tube 74
6, an annular seal member 77 for sealing the tie rod through hole in the rear wall of the booster shell 1 is completely fitted.

The mounting bolt 72 is passed through the front wall W of the passenger compartment of the automobile, and a nut 78 is screwed onto the tip of the bolt 72 and tightened, thereby fixing the tie rod 4 to the front wall W of the passenger compartment.

Thus, the booster shell 1 is attached to the vehicle interior front wall WK via the tie rod 4, and the play master cylinder M is connected to the booster shell 1 via the tie rod 4.

Next, the seal structure between the tie rod 4, booster piston 5, and pinuto/diaphragm 6 will be discussed.

As shown in FIGS. 1 and 3, a pair of tie rod penetration holes 79 are formed in the booster piston 5 between the reinforcing ribs 42, and a plurality of through holes 79, three in the illustrated example, are formed on the rim of the booster piston 5. Notches 80 are provided at equal intervals on the circumference. Further, the piston diaphragm 6 also has a through hole 8 corresponding to the through hole 79.
1 is formed, and a thick portion 82 is formed at the edge of each through hole 81.

As shown in FIGS. 3 and 6, three locking pawls 84 are provided at one end of the outer surface of the two seal mounting cylinders 83, and four locking pawls 84 are provided at the other end, corresponding to the notches 8o. A retaining flange 8G having the entire tool engagement recess 85 is provided in a protruding manner. The top surface 84aK of each locking pawl 84 is formed with a fitting guide inclined surface 84b having a downward inverse slope from the middle portion thereof toward the end surface of the seal mounting cylinder 83.
Further, a rotation guiding inclined surface 84d having a downward inclination is formed from the middle portion of the rising surface 84CKld toward one end thereof. The direction of inclination of the rotation guiding inclined surface 84d in each locking pawl 84 is the same.

The seal mounting tubes 83 are assembled to the sheath stabilizer piston 5 before the valve m14klli is attached to the booster piston 5. Notch 80
It is fitted into the through holes 81.79 of the piston diaphragm 6 and the booster piston 5 in accordance with the above. In this case, the fitting guide inclined surface 84 of the top surface 84a of each locking claw 84
b allows the seal mounting cylinder 83 to fit smoothly into the through hole 79 of the booster piston 5.

Then, as shown in FIGS. 6 and 7, the short cylindrical portion 8 of the tool 87 is
8 to the seal mounting tube 83, and each engaging protrusion 89 on the outer peripheral surface of the short cylindrical portion 88? ] 1 is engaged with each tool engagement recess 85, and a receiver 9 (l) is engaged with the front surface 5a of the booster piston
The handle 91 is rotated entirely in the direction of arrow d in FIG. 7 while pressing the abutment tool 87 and compressing the thick part 82 of the booster piston 5. As a result, each locking pawl 84 is aligned with each notch 8o, and the rising face 84G of each locking pawl 84 and the retainer 7272 are different from each other.
The through holes 79 and 810 of the booster piston 5 and the piston diaphragm 6 are sandwiched between the booster piston 5 and the seal mounting cylinder 83, and the space between the booster piston 5 and the seal mounting cylinder 83 is sealed. In this case, the rising surface Q A c of each locking pawl 84 is
IC, L rlT84 is the through hole 7 of the booster piston 5
It smoothly enters the 90 edge and the clamping is reliably performed.

As shown in FIGS. 2 and 3, the valve cylinder 14 has a retainer 7 and a run 4.
5 includes adjacent locking claws 84 on both seal mounting tubes 83.
Notch 92 having a concave arc-shaped inner circumferential surface that can match the outer circumferential surface between
are formed, and the entire valve cylinder 14 is fitted into the insertion hole 41 of the booster piston 5 to form each notch 92 and each seal recess 4.
When fully fitted with the one cylinder 83, the outer circumferential surfaces near both ends of each notch 92 in the retaining flange 45 form adjacent locking claws 8.
4, the valve cylinder 14 and the seal mounting cylinder 83 are mutually prevented from rotating. As another rotation preventing means, as shown in FIG. 8, a recessed groove 93 that can be engaged with the locking pawl 84 of the book is formed in the notch 92 of the stopper run 45 in the valve barrel 14. Good too.

As shown in FIG.
A sealing means is provided between them to allow the booster piston 50 to operate. The sealing means is constituted by a bellows-shaped telescopic boot 94 made of an elastic material such as rubber.
f: Surrounding, the front end 9a is fitted into the annular groove 95 of the tie rod 4, and the rear end 94b is fitted into the opening of the seal mounting cylinder 83.

In the vehicle interior, at the rear end of the input rod 17 of the booster S, there is a brake pedal 98 that is pivoted 97 on a fixed placket 96.
are connected via a connecting fitting 99. 100 is a return spring that biases the brake pedal 98 rearward.

The rear end of the cylinder body 101 of the brake mask cylinder M penetrates the front wall of the booster shell 1 and enters the first working chamber A, and a booster is installed at the rear end of the working piston 102 in the cylinder body 101. The output rods 34 of S are opposed to each other.

Next, to explain the operation of this embodiment, the state shown in FIG. 1 shows a non-operating state. The valve piston 718 is returned to the predetermined retracted position in contact with the wall 10 and held by the spring force of the spring 37, and then the valve piston 718 presses the front surface of the valve portion 23 via the second valve seat 162. It is moved back until it lightly contacts the front surface of the valve body holding cylinder 21, thereby forming a slight gap g between the first valve seat 16° and the valve portion 23. Such a state can be easily obtained by adjusting the movable stopper plate 35 described above.

According to the above, during engine operation, the first working chamber A, which always stores a full negative pressure, communicates with the second working chamber B through the through hole 26, the gap g, and the through hole 27, and the valve part 23 Since the front opening of the valve is closed by the second valve seat 162, the negative pressure in the first working chamber A is transmitted to the second working chamber B, and the air pressure in both working chambers A and B is balanced. .

Therefore, is the booster piston 5 also the elastic force of the return spring 12? occupies the retracted position shown.

Now, if the brake pedal 98 is depressed to fully brake the vehicle and the input rod 17 and the valve piston 18 are moved forward, the valve portion 23, which is urged forward by the valve spring 25, will follow the valve piston 18. However, since the gap g between the first valve seat 161 and the valve part 23 is extremely narrow as described above, the valve part 23 immediately seats on the first valve seat 161 and the two working chambers A,
B, and at the same time, the second valve seat 162 closes the valve part 23.
It communicates with the atmosphere inlet 11 through the second working chamber B full-through hole 27 and the inside of the valve body 19 apart from the second working chamber B. Therefore, the second
Atmospheric air is quickly introduced into the working chamber B, and the pressure in this chamber B is also higher than that in the first working chamber A. Due to the pressure difference between the two chambers A and B, the sive-staviston 5 resists the return spring 12. Since the output rod 34 is advanced through the elastic piston 3 (l), the actuating piston 101- of the brake mask cylinder M is moved forward.
Drives forward and brakes the vehicle.

1 cylinder main body 10 when the operating piston 102 is driven.
A forward thrust load acts on the vehicle body 1, and this load is transmitted to and supported by the vehicle body, that is, the front wall W of the vehicle compartment via the tie rod 4. Therefore, the above load does not act on the booster shell 1.

On the other hand, the small shaft 33 of the valve piston 18 is moved forward by an elastic screw via the reaction piston 32! - When it comes into contact with the cylinder 3°, the elastic piston 30 is deformed to bulge toward the reaction piston 32 due to the operational reaction force of the output rod 34, and a part of the reaction force is transferred to the brake lever 98 via the valve piston 18. The driver can sense the output of the output rod 34, that is, the braking force.

Next, when the brake pedal 98 is released, the reaction force is applied to the valve piston/18 and the return spring 37 is released.
Due to the elastic force, the input rod 17 retreats, thereby seating the second valve seat 162 on the valve portion 23 and bringing the entire valve portion 23 into contact with the front surface of the valve body holding cylinder 21. Part 23rI
'i, compressive deformation occurs in the axial direction in response to the i direction of the input rod 17. As a result, a gap larger than Todoroki's first gap g is formed between the Ml valve seat 161 and the valve part 23, so that the air pressures in both working chambers A and H quickly balance with each other through this large gap. When the pressure difference between them disappears, the booster piston 5 moves backward by the elastic force of the return spring 12, and the protrusion 13 of the piston diaphragm 6 comes into contact with the inner surface of the rear wall of the booster shell 1 and stops. Then, when the input rod 17 comes into contact with the end wall 10, the valve part 23 is released from the retreating force of the input rod 17 and returns to its original shape, so that the gap with the first valve seat 16□ becomes the small gap g again. It can be narrowed down.

As described above, according to the present invention, each of the locking claws of the seal mounting cylinder and the retaining flange clamp the opening edge of both speed holes of the stabilizer stone and the piston diaphragm, and the seal is sealed between the seal mounting cylinder and the tie rod. Since the means is provided, the double-speed hole can be easily and reliably sealed. Furthermore, it is possible to provide an annular groove or an annular protrusion for attaching the sealing means to the seal mounting tube. Therefore, even if the booster piston is formed from a thin steel plate, the sealing means can be attached to it through the seal mounting tube. Can be installed securely.

[Brief explanation of drawings]

Figures 1 to 7 show one embodiment of the present invention.
The figure is a longitudinal sectional front view of the whole, and corresponds to the case taken along the line 1-I in Fig. 2.
Fig. 3 is an exploded perspective view of the booster piston, piston, diaphragm, valve cylinder, locking plate, and seal mounting cylinder, and Fig. 4 shows the valve cylinder relative to the booster piston. 5 is a partially enlarged longitudinal sectional front view showing the sealing structure between the booster piston and the valve barrel, FIG. 6 is a perspective view showing the relationship between the door mounting barrel and tools, and FIG. FIG. 7 is a cross-sectional view showing how the seal mounting cylinder is attached to the goose-taviston, and FIG. 8 is a partial side view of a modification showing the relationship between the valve cylinder and the seal mounting cylinder. A, B... 1st. 2nd working chamber, 1... booster shell, IF, IR... bowl-shaped body, 4
...Tie rod, 5...Booster piston, 6...
・Piston diaphragm, 8...control valve, 79.81
. . . Through hole, 80 .

Claims (1)

[Claims] Inside the booster shell, which has a pair of front and rear bowl-shaped bodies, is a booster piston that can freely reciprocate back and forth, and a piston diaphragm attached to the rear surface of the booster piston. It is divided into a working chamber and a rear second working chamber which is alternately controlled to be communicated with the first working chamber or the atmosphere via a control valve, and the arm-shaped body is connected to the piston diaphragm and to the booster piston. In a negative pressure booster which is connected by a tie rod passing through both formed feed holes and sealed both feed holes, a plurality of notches are all provided on the edge of the through hole of the booster piston, and the By inserting and rotating a seal mounting tube, which has a plurality of locking claws corresponding to the notches and seven retainers facing each of the locking claws, into both feed holes and rotating, each of the locking claws and A negative pressure type booster characterized in that both feed hole mouth edges are fully clamped between the retaining flanges, and a sealing means is provided between the seal mounting cylinder and the tie rod.